The background art will be described by way of an example of a hybrid excavator.
As illustrated in FIG. 5, a hybrid excavator includes a crawler-type lower traveling body 1, an upper slewing body 2 mounted on the lower traveling body 1 so as to slew about an axis perpendicular to the ground surface, and various facilities and devices such as a cabin 4 mounted on an upper frame 3 provided in the upper slewing body 2 as a base. Moreover, a working attachment A including a boom 5, an arm 6, and a bucket 7 is mounted on a front portion of the upper frame 3.
In this specification, the directions “front-rear direction” and “left-right direction” are defined when the position of the cabin 4 is on the left front side.
As illustrated in detail in FIG. 6, the upper frame 3 includes a center section C having a pair of left and right vertical plates 8 serving as a reinforcing member and an attachment mounting member and side decks D1 and D2 provided on both left and right sides of the center section C. An engine 9 as a power source is provided in a rear portion of the center section C.
Moreover, the hybrid excavator includes an generator motor 10 and a hydraulic pump 11 provided on the right side, for example, of the engine 9. The generator motor 10 as a hybrid device operates as a generator and a motor and the generator motor 10 and the hydraulic pump 11 are arranged in the left-right direction.
A cooler 14 and a cooling pump 15 for cooling the hybrid device are provided on the left side of the engine 9 in addition to a radiator 12 and a cooling fan 13 for cooling the engine.
On the other hand, a control unit (inverter) 16 that controls the operation of the generator motor 10 and an electric storage device (not illustrated) as a hybrid power source are provided in a front portion of the right side deck D2. The control unit 16 and the electric storage device are disposed in a vertically stacked state so that the control unit 16 is positioned above and the electric storage device is positioned below, for example. A tank (for example, a fuel tank) 17 is provided on the rear side of the electric storage device and the control unit 16 of the right side deck D2.
The electric storage device may be disposed at a position different from the control unit 16. Moreover, an operating oil tank may be provided instead of the fuel tank 17 and both tanks may be arranged in the front-rear direction or the left-right direction.
Moreover, a slewing motor 18 as a slewing drive source is provided approximately in a central portion of the center section C.
Hereinafter, the generator motor 10, the control unit 16, the electric storage device, and the slewing motor 18 each are sometimes referred to as hybrid device.
In such a hybrid excavator, the hybrid devices (the generator motor 10, the control unit 16, and the electric storage device) are connected by an electric wire such as a power cable for transferring electric power or a signal cable for exchanging a control signal (see Japanese Unexamined Patent Application Publication No. 2012-184586).
Moreover, since it is necessary for these hybrid devices require to be cooled and to be heated, as disclosed in Japanese Unexamined Patent Application, Publication No. 2012-154092, the hybrid devices (the generator motor 10, the control unit 16, and the electric storage device) are connected by liquid pipelines (in the following description as well as the embodiment of the present invention, water pipelines which uses water as a cooling/heating medium is used). Moreover, the hybrid device, the cooler 14, and the cooling pump 15 are also connected by liquid pipelines.
In a hybrid excavator in which water pipelines and electric wires are wired on the upper frame 3 in a state where the water pipelines and the electric wires are mixed together, the following problems may occur in a hybrid device to which both a water pipeline and an electric wire are connected.
For example, the control unit 16 may have a casing that is quadrangular in a plan view thereof and a pipeline connection opening and a connection terminal formed on a side surface of the casing. A water pipeline may be connected to the pipeline connection opening and electric wires (a power cable and a signal cable) may be connected to the connection terminal.
In this case, when connection portions of the pipelines and the electric wires are disposed close to each other on the same surface of the casing, if water leaks from the pipeline connection portion or the vicinity thereof due to a connection failure, or cracks, ruptures or the like in the pipeline, the leaking water may fall directly on the electric wire or the connection terminal.